Molded article and method of making the same



W. H. KEMPTON.

MOLDED ARTICLE AND METHOD OF MAKiNG THE SAME.

APPLICATION FILED OCT. 8. 191a.

1,370,024, Patented Mar. 1, 1921.-

UNITED STATES .g TE T oFF1cE.

wItLAan n. KEMPTON', or WILKINSBURG, rENNsYLvAnIA, assrenon 'ro wnsrme- HOUSE nnnorarc & menumcrnnme COMPANY; A oonron'mron or PENNSYL- value.

' To all whom. it may concern Be it known that I, WILLARD H. KEMP- TON, a citizen of the United States, and a' resident of Wilkinsburg, in the county of' My inventionrelates to rods, tubes and the like comprising superimposed layers of impregnated sheet material having screw threads molded therein, and it has for its primary-object the'construction of. such articles by a method which will insure a cheap and highly eflicient product.

Heretofore, difliculty has been experienced in constructing strong threaded rods, tubes and the like comprismg superimposed layers of impregnated sheet material by 'cuttin the threads in the surface of themate- On account of the laminated. struct-ure of such articles, the cutting away of material to provide threads weakens the structure because only the binding action of the adhesive employed secures in place the layers of material constituting the threads. In view of'this, one object of my invention is to construct rods, tubes and the like of impregnated sheet material and mold threads in their surfaces, thus eliminating any tendency to weaken the structure by cutting the material.

Another object of my invention is to manufacture rods, tubes' and the like of impregnated sheet material by a method'in the employment of which the articles may be threaded, pressed and cured in a single operatioh. A further object of my invention is 'to provide rods tubes and the like having threaded surfaces of such character that the greatest strength shall be at the points of greatest stress.

A further object of my invention .is to construct articles of impregnated sheetmaterial havin threaded surfaces molded thereon whic shall be unaffected by wide temperature changes, moisture, oils, weak acids and alkalis. v

A still further object of my invention is to construct tubes of impregnated sheet ma- Speclfication of Letters latent.

MOLDEli) ARTIGLEJAN D METHOD OI MAKING THE SAME.

Patented Mar. 1, 1921.

Application filed. October a, 1918. Serial No. 257,390.

terial by amethod which may be employed A to provide threadson the inner or. the outer surfaces of the tubes with the same facility. With these and otherobjects in view, my mvention will be more fully described; illustrated in the drawings, in the several views a fragmentary, sectional view,of a tube, em-' bodying my: invention, disposed about a mandrel which is shown in elevation, the

dispostion of the material being exagger-- ated to clearly brmg out the method of 'con-' struction; Fig. 4 is a sectional view of a tube similar to that shown in Fig. 3 and illustrating the threading of the inner surface of a tube, a threadedmandrel, em-

ployedin this -instance,-being shown in elevation.

of which corresponding numerals indicate l1ke parts, and then. more particularly igure 1 is a longitudia- In practising my invention, I may con- I struct a tube by impregnating suitable sheet' material wlth a binder, such, for example, as aphenolic condensation product, and winding such material about, a mandrel, after which the mandrel and the material dis-- posed about it may be placed in a suitable The mold may have-forming members, which may be provided with mating thread sectlons, which, when the members, are disposed .so as to surround the mandrel and the. in-

closing material and'heat and pressure are mold and subjected to heat and pressure.

applied, coact to form .threads on the surtube is desired having its inner surface threaded, the impregnated material may be wound about a threaded mandrel, and the mandrel and surrounding material ma ,be disposed in a mold and subjected to eat and pressure.

Rods maybe constructed by themethod employed in forming tubes, the only difier- 'ence being that the material is'wound upon,

itself to form 'a solid roll rather than about a mandrel. The same method'is employed -to form the threads onthe surface of the rod.

In Fig. l'is shown .a mold 1 which may be employed in constructing rods, tubes and the like in accordance with my invention, the mold, being of ordinary design, is here shown merely to clearly set forth the method of constructmg rods or tubes in accordance with my invention and, on this account, only a'brief description will be given of the mold and its several parts. The tube 2, shown inclosed in the mold 1, may be constructed by impregnating a sheet material, such as paper, duck, muslin, or cotton batting, with a suitable binder, such, for example, as a phenolic condensation product, after which the material may be dried to facilitate the handling of it. The material may then bewound about a mandrel 3 until a' suitable thickness has been reached, and the mandrel 3 andthe material disposed about it be surrounded b threaded forming members 4:, 5, 6 and 7 o the mold 1. The mandrel 3 and inclosing forming members 4; 5, 6 and 7 may then be placed in the mold 1 so that the bottom forming member 5 rests upon, and is supported by, a bottom clamping plate 8 of the mold 1, which also supports the rectangular frame 9 of the mold 1, which has projecting edge portions 10. The bottom clamping plate 8 has upwardly extending flange portions 11 which are interiorly undercut and provided with wedge faces 12 so that wedge-shape openings are provided between the undercut flanges 11 and the exv tending portions 10 of the wall 9 of the mold 1. The wall 9 of the mold 1 has recesses 13 provided in which the ends of the mandrel 3 seat and are thus prevented from movement toward either side. The wedge members 14: may then be forced between the side forming members 6 and 7 and the wall 9 of clam ing the mold l, and-a top clampin plate 15 may be placed on the wedge mem ers 14. The clam ing plate 15 has downwardly projecting angie portions 16 interiorly undercut to'provi e openings between the extending ange portions 10 of the mold 1 and the downwardly projecting portions 16 of the late 15 when it'is forced into position. edge members 17 may be driven 1nto the openings thus provided by the up- 'per and lower clamping plates 8 and 15 to hold the mold tions. v

Rods may be constructed'in the manner described for forming tubes except that the impregnated material may be wound upon elements in their final posi- -itself'to form a solid roll instead of being wound about a mandrel, or the material may be wound about a preformed core of material similar to that constituting the outer layers, and the rod thus formed may be disposed in a mold, such as is shown in.

After the tube thus formed is pressed and" cured in a mold,'it may be cooled and 'the mandrel may be removed by rotating it until forced out of the tube by the screw action.

Both rods and tubes constructed in the -manner disclosed have threaded surfaces in which material is compacted more in some portions than in others, the denser portions of the material having greater mechanical strength than the less compacted portions. Since the stresses to which the threads are subjected are greatest near the bottoms of the groove portions, the greater mechanical strength attained at these places is of decided advantage. Furthermore, since the material is not cut to provide the threaded surface, the strength obtained by a continuous layer of material is retained.

Although I have described specifically the construction of rods, tubes and the like in accordance with my invention, it will be obvious that minor changes may be made therein without departing from the spirit thereof, and I desire, therefore, that no limitations shall be imposed except such as are indicated in the appended claims.

I claimas my invention:

1. A body formed ofspirally wound sheet material and a hardened binder, the body having pressed-in portions providing a resultant screw thread in which the several layers of the sheet material are disposed substantially parallel to the faces of the thread.

2. A body formed of spirally wound sheet material and a hardened phenolic condensation product,- the body having pressed in portions providing a resultant screw thread in which the several layers of the sheet material are disposed substantially parallel to the faces of the thread.

3. The method of constructing threaded win ing a binder impregnated fibrous sheet into a roll and subjecting the roll to heat and transverse pressure in a mold of a character such as to cause crimping of outer 'rodsi tubes and the like which comprises layers of the sheet material to provide a threaded tubes which comprises impregnating sheet material with a binder, wmding the impregnating material. about a threaded mandrel, disposing the mandrel and the material wound about it in a suitable mold and applying heat and transverse pressure to compact the material and harden the binder.

5. The method of constructing interiorly threaded tubes which comprises impregnating sheet material with a phenolic condensation product, winding the impregnated material about a threaded mandrel,

disposin the mandrel .and the material 10 wound a out it in a suitable mold and applying heat and transverse pressure to compact the material and harden the binder.

In testimony whereof I have hereunto subscribed my name this 25th day of Sept. 15 1918.

WILLARD H. KEMPTON. 

